Hole Finder

There are a few accomplished and talented brains here that can help
with this. We have a tailwheel steering control horn with holes
already drilled at right angles through its long shaft for two AN-3
bolts-- to fix it inside the rudder's vertical tube. Now when the
shaft is inserted up inside the 4130 tubing of the new rudder, what
would be the best way to drill the rudder's tube accurately, without
missing the holes in the shaft or wallowing them out? Those two AN-3
bolts are in shear and of course fasten the tailwheel steering horn to
the rudder. We want precision, and no slop. The old rudder's holes
looked like hell.

I can see where the problem was encountered elsewhere and the holes in
the tailwheel steering horn were elongated, then welded back and
re-drilled-- not such a good idea since the control horn is aluminum
alloy.

Ever seen that little mag-pecker device that lets you find a blind hole
you need to drill through to? There is a magnet centered in the blind
hole, which a sharp needle points to, making a prick in the precise
spot where you drill. Well, I don't think it will work here, but bet
you could make one that would.

TIA and apologise for all the Freudian terms.